<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			img {
				position: absolute;
				top: 0px;
				left: 0px;
			}

			img:hover {
				/* 堆叠顺序 */
				z-index: -1;
			}
			
		</style>
	</head>
	<body>
		<img src="img/def.jpg">
		<h3>学掌门</h3>
	</body>
</html>
